Prosecutors say Slagley's pleading guilty to the killings and the sex crimes were part of a deal that got Slagley a total of 30 years in prison.

Slagley's attorney did not immediately respond to a request for comment.

Although Slagley did not intend to kill Hill or her unborn child, prosecutors said they charged him with murder under the concept of "transferred intent."

Chief Assistant Prosecuting Attorney Todd Myers explained in 2017 that when an individual intends to kill someone, what matters under Missouri law is that there was the intent to kill. While the targeted victim wasn't harmed, Myers said, a person can still be guilty of murder.